/* DBC / BIOTEN V4.1.0 — restrained progressive enhancements. */
(function () {
  'use strict';

  if (window.__DBC_SITE_V410__) return;
  window.__DBC_SITE_V410__ = true;

  document.documentElement.classList.add('v410-js');

  function initNewsroomIndex() {
    const page = document.querySelector('main[data-v410-news-index]');
    if (!page) return;

    const anchorBar = page.querySelector('.news-business-anchor');
    const anchors = anchorBar
      ? Array.from(anchorBar.querySelectorAll('a[href^="#"]'))
      : [];
    const panels = anchors
      .map(function (anchor) {
        const id = anchor.getAttribute('href').slice(1);
        return document.getElementById(id);
      })
      .filter(Boolean);

    function setActive(id) {
      anchors.forEach(function (anchor) {
        const active = anchor.getAttribute('href') === '#' + id;
        anchor.classList.toggle('is-active', active);
        if (active) anchor.setAttribute('aria-current', 'location');
        else anchor.removeAttribute('aria-current');
      });
    }

    anchors.forEach(function (anchor) {
      anchor.addEventListener('click', function () {
        setActive(anchor.getAttribute('href').slice(1));
      });
    });

    if ('IntersectionObserver' in window && panels.length) {
      const observer = new IntersectionObserver(function (entries) {
        const visible = entries
          .filter(function (entry) { return entry.isIntersecting; })
          .sort(function (a, b) { return b.intersectionRatio - a.intersectionRatio; });
        if (visible[0]) setActive(visible[0].target.id);
      }, {
        rootMargin: '-28% 0px -58% 0px',
        threshold: [0, .08, .2]
      });
      panels.forEach(function (panel) { observer.observe(panel); });
    }

    const hashAliases = {
      'featured-evidence': 'bioten-news',
      'partnerships': 'casu-news',
      'brand-ecosystem': 'antux-news',
      'archive': 'dpu-news'
    };
    const hash = window.location.hash.slice(1);
    const activeId = hashAliases[hash] || hash;
    if (panels.some(function (panel) { return panel.id === activeId; })) {
      setActive(activeId);
    } else if (panels[0]) {
      setActive(panels[0].id);
    }

    const archive = document.querySelector('#dpu-news .news-card-grid');
    if (!archive) return;
    const cards = Array.from(archive.querySelectorAll('.news-event-card'));
    const initialCount = window.matchMedia('(max-width: 760px)').matches ? 8 : 12;
    if (cards.length <= initialCount) return;

    let expanded = false;
    const control = document.createElement('div');
    control.className = 'v410-archive-control';
    const button = document.createElement('button');
    button.type = 'button';
    button.setAttribute('aria-expanded', 'false');
    button.setAttribute('aria-controls', 'dpu-news');
    control.appendChild(button);
    archive.insertAdjacentElement('afterend', control);

    function renderArchive() {
      cards.forEach(function (card, index) {
        card.hidden = !expanded && index >= initialCount;
      });
      button.setAttribute('aria-expanded', String(expanded));
      button.textContent = expanded
        ? '收起历史归档'
        : '展开全部历史归档（' + cards.length + '）';
    }

    button.addEventListener('click', function () {
      expanded = !expanded;
      renderArchive();
      if (!expanded) {
        document.getElementById('dpu-news').scrollIntoView({
          behavior: window.matchMedia('(prefers-reduced-motion: reduce)').matches ? 'auto' : 'smooth',
          block: 'start'
        });
      }
    });

    renderArchive();
  }

  function labelUnavailableLanguageControl() {
    document.querySelectorAll('[data-language-unavailable]').forEach(function (button) {
      button.setAttribute('aria-disabled', 'true');
      button.setAttribute('title', '本页英文内容正在校对，当前提供完整中文版本');
      button.setAttribute('aria-label', '本页英文内容正在校对，当前提供完整中文版本');
    });
  }

  function guardLocalPreviewForms() {
    if (window.location.protocol !== 'file:') return;
    document.querySelectorAll('form').forEach(function (form) {
      form.addEventListener('submit', function (event) {
        event.preventDefault();
        event.stopImmediatePropagation();
        const status = form.querySelector('[role="status"], .request-status, .form-status, [data-form-status], [data-request-status]');
        const message = '当前为本地预览，页面内容可完整检查，但不会发送表单。正式部署后再进行真实提交。';
        if (status) {
          status.hidden = false;
          status.textContent = message;
        } else {
          window.alert(message);
        }
      }, true);
    });
  }

  initNewsroomIndex();
  labelUnavailableLanguageControl();
  guardLocalPreviewForms();
})();